In recent years, thin film transistor liquid crystal display (TFT-LCD) gradually dominates the market of flat panel display due to its advantages of lower power consumption, no radiation and so on.
FIG. 1 is a plan schematic view illustrating a portion of an array substrate in a conventional TFT-LCD. FIG. 1a and FIG. 1b are enlarged views of regions M and N in FIG. 1. FIG. 2 is a sectional view taken along line A-A′ in FIG. 1. A common electrode and a pixel electrode are provided on the array substrate. The common electrode 1 is a plate electrode. The pixel electrode 2 has a plurality of strip electrodes. The pixel electrode 2 is provided above the common electrode 1. A fringe electric field Ef is formed between the pixel electrode 2 and the common electrode 1. There is a large overlap region between the common electrode 1 and the pixel electrode 2, that is, the projection of the common electrode 1 on a base substrate of the array substrate and the projection of the pixel electrode 2 on the base substrate have a large overlap region, and therefore the storage capacitance formed between the common electrode 1 and the pixel electrode 2 is relatively large. In the TFT-LCD has the array substrate described above, defects relating to the charge and discharge of pixel easily occur. This problem may be more serious for the TFT-LCD with big size and high frequency.